Modem manufacturing and prototype operations have created a demand for manufacturing equipment which can be readily produced and assembled for the purpose of producing prototype and short-run components by various methods. As a particular example, current computer-aided design and manufacturing technology which is employed to develop dies used in metal forming processes often rely on computer simulations of the particular metal forming process to reduce the design time and tooling costs for the die, as well as the time necessary to verify the design of the die. The quality of the finished die directly impacts the quality of the article produced. Thus, a rapidly produced die of lesser quality may result in additional time and costs to finish the article, which therefore increases the overall time and cost required to produce a finished article. Consequently, dies which are rapidly designed to be economical for use in prototype and short production runs are often achieved as a trade-off in die quality and life.
Nonetheless, much attention has been devoted to the development of processes for the rapid manufacturing of dies, particularly draw dies used in stamping operations. The benefits associated with rapidly produced draw dies are apparent. As an example, lower cost dies offer a manufacturer the opportunity to compete in niche or limited volume markets. In addition, the ability to rapidly obtain a draw die when developing a process facilitates the ability to have a component ready for prototype assembly, while also subsequently facilitating the production line die design.
However, rapidly produced dies have a significant disadvantage, in that such dies can be more readily made if produced from materials which are softer than the conventional cast iron used. In particular, this issue is paramount when attempting to obtain "cast-to-size" dies, which generally employ plastics or other less durable materials which have a lower melting point than cast iron. As a result, the durability of rapidly produced dies is often inferior to that of conventional dies, such that some limitation must be placed on the volume of parts produced from the die before the die requires reworking or reconstruction.
A suggested alternative to conventional methods of die making has been the use of an assembly of hard metal rods or pins which are frictionally held together by a suitable frame member. The hard metal rods provide a more durable die surface than the materials typically used for rapidly-produced dies, such as those noted above. An obvious disadvantage is that the die surface will not be smooth. However, a less obvious disadvantage associated with the use of the rods is that of achieving accurate rod placement. One approach is to use a reverse model of the desired surface. However, this approach negates much of the time advantage sought by seeking a rapidly-produced die, since forming a suitable model is often time consuming and costly.
To alleviate the need for a model, it has been suggested to use electromechanical drives and sensors to position the rods to their assigned positions based on known surface data for the article to be produced. However, the friction between adjacent rods which serves to keep each rod in its proper place also tends to dislodge adjacent rods while an individual rod is being positioned. If all of the rods are being positioned simultaneously to overcome this drawback, the driver and sensor system tends to be much too complex for a die of any significant size.
Thus, it would be desirable to provide a die which could be rapidly produced, assembled and adapted for a particular use in a minimal amount of time, so as to be particularly suitable for use in manufacturing prototype and short-ran components. The above discussion is also applicable to the making of molds for molding processes, such as for plastic molding and die casting operations, as well as for other manufacturing processes, such as machining and welding operations, which have conventionally required different solutions. Similar to the situation described above for dies, modem manufacturing and prototype operations have created a demand for fixtures which can be readily produced and adapted for the purpose of producing prototype and short-ran components by various machining and joining methods. Also similar to dies, the ability to rapidly produce a fixture having the proper dimensional characteristics for a given component becomes of great importance, particularly for prototype and short-ran articles, wherein the time and costs required to produce the necessary fixtures represents a significant proportion of the total manufacturing time and costs for the article to be produced.
Fixturing irregularly-shaped parts is often quite tedious, particularly where the article being fixtured does not have suitably rigid locations for restraining the article, such that the article tends to be distorted by the forces generated by the fixture to secure the article. Customized fixturing is often required to properly support, locate and clamp such articles, resulting in fixtures that are both time consuming and costly to produce. Again, such fixturing is not an economical option when prototype or short-run production is the goal, particularly in view of the fact that a specially configured fixture will most likely be unsuitable for use with any other article.
Thus, as stated previously, it would be desirable to provide manufacturing equipment, such as dies, molds and fixtures, which could be rapidly produced, assembled and adapted for a particular use in a minimal amount of time, so as to be particularly suitable for use in manufacturing prototype and short-run components. Such rapidly-produced dies and molds would only be feasible if they could be readily and accurately produced, such that the time necessary to develop the dies and molds was minimized. Suitable rapidly-produced fixtures would preferably be readily adaptable and reconfigurable so as to locate, support, and clamp components having various geometries and shapes, such that the fixtures would be reusable and therefore economical for use in manufacturing prototype and short-run components.